Magnetic separator



July 22, 1958 E. M. FURNESS MAGNETIC SEPARATOR Filed'July 14, 1955INVENTOR;

'ow ko M/msss "M ATTORNEYS United States Patent serve Mining Company,Duluth, Minn., a corporation of Minnesota Application July 14, 1955,Serial-No. 522,063

8 Claims-., (Cl.,209-223) The present invention relates to a magnetseparator which is used in connection with separating magnet-izablematerial from its comingled material, for example, separating magneticore bearing material from its comingled gangue or tailings. Insuchapparatus, the material to be operated upon is in coarsely groundcondition (8 to 1-0 mesh) and mixed with water, the said mixture beingfed to the magnetic separator and passed through amagnet seal wherebythe magnet portion of the material being treated is separated andrecovered while the non-magnetic material or the gangue or taiIin gs is.rejected by the apparatus and then conveyed to a place of disposal.

Without any intention of limitation, the present invention iseffectively usable in separating the metallic bearing portions of ironore containing material, as an: example of which may be mentioned,taconite which contains iron oxide in a gangue of non-metallic foreignma.- terial.

An object of the invention is to. provide a revolvable drum within whichis located electrically energized pole members and employing a belt ofnon-magnetic material which is in contact with the peripheral portion ofthe drum and further in providing means which insures ample contact ofthe belt with that portion of the drum subjected to the magnetic eifectof the pole members and even somewhat beyond such portion, so that themagnetically separated material will not prematurely be released fromthe belt but retained thereon until reaching the selected point ofdischarge.

The arrangement and use of a belt of non-magnetic material, takes thewear, incident to passing the coarsely ground material intocontact withthe-beltand. such wear, does not decrease the efliciency with respect toseparation of the apparatus, which'would' bev the case if such a beltwere not used as will be later pointed out- The above object ofinvention may be obtained either by using a single revolvable-drumwithin which is located electrically energized pole members and aroundwhich a beltof non-metallic material is associated, together with adriving pulley which is associated with another portion of the belt,with which said assembly is associated, the means associated with thebelt and adjacent the revolvable drum with which the electricallyenergized pole members are associated, so as to insure a greater surfacecontact of the belt with the drum than would otherwise be the casewithout the use of such means.

A further object of the invention is to provide a magnetic separatorinvolving the use of two revolvable drums with which a continuous beltis associated and contacting major portions of the peripheral surface ofeach of the drums.

A more efficient separation of the magnetic material can be obtained bysubjecting the material to a retreatment of the ore by means of a secondmagnetic field. When ore such as magnetite passes over a magnetic drumof the type described, the particles of magnetitenot only adhere to thesurface of the drum, or more particularly, to

the surface of the belt which; engagement with they .the drums.

Patented July 22, 1958 "ice drum, but they also adhere to each other dueto the fact that the-particles of the material act as little magnets.When, therefore, upon reversing polarity of the magnets in thedrum,there-is caused a relative movement between the particles of ore, suchmovement tends to shake loose the more weakly or'non-m-agneticparticles. However, this relative movement is more completelyaccomplished after the ore has been removed from the mag netic fieldsbecause the particles no longer adhere to each other, with great force.Therefore, a plurality of drums or other types of magnetic separatorsmay be more effective than one drum, regardless of the size or number ofmagnetic poles.

Where a plurality of drums are used as above suggested, an idler pulleymay be used which is located between the drums so as to cause the beltto travel in a loop between the drums and thereby affect a greaterportion of the periphery of the adjacent portions of each drum, beingthus. engaged by the belt. This insures engagement' between the belt andthe periphery of each of the: drums throughout the portions of theperiphery of the drums which are subject to the magnetic field and evenwhere desired, a greater area of engagement.

An important result obtained by the use of the appanatus which is hereindescribed, that the belt protects the: surface of the drum from anypitting and blistering actionand' wear which invariably results whererelatively coarse. material to be separated is brought directly intocontact: .with the peripheral surface of the drum rather than by the useOf a belt which moves upon the periph cry of the drum.

In the foregoing connection it should be mentioned that. where there isa pitting or blistering of the drum surface, the operation of themagnetic field with respect to the:material whichis fed into contactwith the drums, becomes subject to a varying intensity which mayappreciably afiect the metallurgical properties of the material which isbeing, separated by passage through the magnetic field. In other words,the use of a belt, at least in such a relationship as is hereindisclosed, tends to assure a uniform magnetic field in its applicationto the materialwhich is to be treated and which undergoes separation, sothat the intensity of the magnetic field does not vary during the timewhen the material to be separated is in contact with that portion of thebelt which is subjected to the action of a magnetic field.

Other features of the separator which is herein disclosed will beapparent as the description proceeds.

Referring to the drawings,

gig, 1 is a. top plan viewof the magnetic separator; n

Fig. 2 is a side elevation with portions in section showing. therelationship of the drum with respect to the belt and the intermediatepulley which also cooperates with the. belt.

Referring to the drawings, 1 generally indicates a. base member which isprovided with upstanding leg portions 2, which legs at their upper endare joined by a transversely extending member on both sides which isindicated by the reference numerals 3 and 4 respectively.

Extending transversely of this frame are two shafts which are indicatedat 67 and which rotatably support drums 8 and 9. Within each of thedrums there are a series. of pole members which are indicated at 10 and11 which occupy the lower part of each of the drums and which areenergized by an electric current to provide a proper magnetic field,which is effective upon what might be called the lower peripheralsurface of each of Permanent magnets may also be employed. It is notproposed to go into detail as to the construction ,and'operation ofapparatus which produces the magnetic field, inasmuch as thisis amatterof design and the use of such magnetic field producing device isthoroughly well known in the art.

Extending around each of the pulleys is a continuous belt 12 which isparticularly shown in Fig. 2 of the drawings. Intermediate of the drumsand mounted upon a support 13, which in turn is mounted upon the frameof the machine, is a pulley 14 which is adjustably mounted in thesupport 13. This pulley or roller as it may be termed, is so positionedthat the traveling belt continually passes over the pulley 14 in thecourse of the traveling movement of the belt. The pulley 14 is mountedso that it is above a plane passing through the center of each of thedrums 8 and 9. The etfect of this is that it provides for peripheralcontact between the belt and those portions of the drums which areadjacent to each other, of considerably greater extent than would bepossible if the pulley were not used.

This is important not merely as a structural feature, but because itenables the magnetic material to be cleaned from the belt after it hasbeen subjected to the respective magnetic fields and therefore providesfor more efiective operation not only of the magnetic field but for theremoval of the material from the belt as the material will have passedbeyond a point with respect to the periphery of the drum where themagnetic intensity has effectively diminished and where, therefore, thematerial which is adhering to the belt may be removed.

Beneath each of the drums is a hopper such as indicated at 15 and 316and at the lower end or bottom of each hopper there is an exit pipe, oneof which is shown at 17, by which the non-magnetic material, such asgangue or tailings, collecting within the respective hoppers, may bedischarged.

Adjacent one of the drums and more particularly as shown, the drum 8,there is a receiving trough or compartment which is shown at 18, thisbeing somewhat elongated and is provided with means for spraying watertherein, one of which means is shown at 19 in Fig. 2.

Material which is to be acted upon by the magnetic separator, isintroduced through the induct 20, which material in every case is infinely divided form and mixed with water.

In using magnetic separation which is a part of the process ofconcentrating taconite ores, the material supplied will frequently bethat which comes from a rod mill which is as well known, is a device forproducing finely divided material and which finely divided material asdischarged from the rod mill is in flowable condition because of itswater content.

At the lower end of the trough-like member 18 there is a chute 21 whichat its inner end overlies the upper edge of the hopper 15 and this chuteextends to a point which is adjacent to the periphery of the drum 8 sothat material introduced into the hopper 18 and through the chute 21moves into proximity with the belt, at the periphery of the drum 8 whichis adjacent to the lower portion of the chute.

Located between the drums 8 and 9 and below a horizontal plane passingthrough the centers of the drums is a V-shaped shed member indicated at22, one surface of this shed member lying adjacent to the peripheralportion of the drum 8, the V-shaped member also having its one sideextending within the wall of the hopper 15.

The surface of the \'-shaped member 22, to which reference has just beenmade, will direct any tailings of material which may mechanically adhereto the magnetic material upon the belt and which may drop therefrom asthe belt moves in juxtaposition to the surface of the member 22 which isadjacent to the hopper 15.

This V-shaped member is formed with a surface which is adapted tocooperate or form a part of a chute 23 which is so mounted as to be injuxtaposition with relation to the lower portion of the drum 9. Thechute 23 receives material which may be deflected by the member 22,which material has been released from contact with that portion of thebelt which was in engagement with the drum 9 at the end portion of themagnetic field. This chute 23 directs material to a place where it isclose to that portion of the belt engaging upon the lower portion of thedrum 9 and which is adjacent to the chute 23. This chute at its lowerportion communicates with the hopper 16. It will be noted that the lowerportion of the chute 23 is adjacent to that portion of the drum 9 wherethe magnetic field is set up by the magnetic pole pieces within the drumso that material descending through the chute 23 is subjected to themagnetic field, to which reference has just been made, and the magneticmaterial thus passing through the chute is drawn into contact with thebelt and carried by the belt, as will be apparent from an inspection ofFig. 2.

Between the drums 8 and 9 there is located a spraying device 27 whichextends transversely across and in parallel relationship with the drums,this spraying device being positioned to spray water upon the belt atthat portion thereof which in its travel comes above the upper end ofthe V-shaped shed 22.

At the end of the apparatus which is beyond the drum 9 there is locateda trough 28 which is adapted to be connected with a water pipe forfilling-the same which is located at 29 and which water pipe isconnected with a water pipe 30. The trough is positioned so that thetrough as it overflows discharges water into proximity to the belt at apoint above the horizontal diameter of the drum, this discharge portionbeing indicated at 28a.

Reference to both the spray 27 and the trough 28 and noting theirposition with respect to the drums 8 and 9, it will be seen that thespray 27 will contact that portion of the belt which is passing from theinfluence of the magnetic apparatus within the drum 8 so that themagnetic force applicable to the material which is carried by the beltwill be weakened and by the operation of the spray 27 impinging uponthis material and causing water in part to flow down upon the belt willcause the material to drop away from the belt and be directed by thell-shaped member 22 toward the upper end of the trough 23.

Likewise, it will be apparent that the water discharged from the trough28 upon the belt, will in a large part run down upon the belt and assistin separating the ore material from the belt in that portion thereofwhich is passing from the magnetic field so that such material will fallfrom the belt upon the member 24 and be directed toward the exit chute26.

The operation of the herein described magnetic separator will beapparent from the description and from the drawings, and as will beseen, provides for initial separation by a magnetic field of themagnetizable material from the gangue or tailings and which initiallymagnetically separated material is subjected to a second separatingoperation by passing through the magnetic field associated with thesecond drum, and the finely delivered separated material is in a stateof much higher refinement than would be obtained by passing the materialthrough a single magnetic field.

Moreover, the provision of the pulley 14 over which the continuous beltpasses provides for a longer period of time for peripheral engagementbetween the belt and the drum 8 so that the magnetized material carriedupon the belt will not be discharged therefrom until such material willhave passed beyond the magnetic field induced within the drum 8 andabove the apex of the member 22,

thus insuring that such material when released from the belt, whichoperation is assisted by the water spray 27, will fall upon'that surfaceof the member 22 which leads drum 9 by virtue of the operation incidentto passing the belt over the pulley 14.

The disclosure contained in this application embodies the specific formin which the invention has been embodied but variations in the preciseconstruction may be made; and embodying the operating functions of theapparatus herein disclosed, without departing from the spirit of theinvention-as expressed-in the claims appended hereto;

Having" thus described my invention, I claim:

1. A magnetic separator comprising a drum mounted for rotation about itsaxis, an: endless belt engaging with the periphery of said drum andadapted to travel as the drum is rotated, a hopper mounted beneath thesaid drum, a chute for delivering material to the belt upon theperiphery of the drum and adjacent the lower portion of the said drum;a. magnetic device within the drum for creating a magnetic field at thelower portion of the drum, means engaging with the belt and located atone side of the drum and above the horizontal diameter there of forbiasing the belt so that it will travel in contact with theperipheralsurface of the drum to a point beyond and above the positionof the magnetic device within. the drum,- means for delivering waterupon the belt at a position approximating the point where the beltleaves contact with the periphery of the drum, a shed located at oneside of. and beneath that portion of the drum where the belt leaves thedrum and passes to the means which biases the movement of the belt, saidshed having a surface which cooperates with the hopper and having anopposite surface which deflects magnetically separated m aterialt awayfrom the said-mentioned drum.

2. A magnetic separator comprising a horizontal drum mounted forrotation about its axis, an endless b'elt engagingwith the periphery ofsaid drum and adapted to travel in the same direction as the drum isrotated, a hopper mounted beneath the said drum, a chute having adischarge end for delivering material to the belt upon the periphery ofthe drum adjacent the lower portion of the drum' the said drum rotatingin a direction such that the movement of the belt is away from thedischarge end of the chute, a: stationary magnetic device within thesaid drum for creating a magnetic field at the lower portion of the drumonly, a rotatably mounted member over which. the said belt moves thesaid member being mounted at the side of the drum in thedirectionxoftbelt movement and above the horizontal diameter of the saiddrum, the said member being positioned so that a portion of the beltremains in contact with the peripheral portion of said side of the drumto a point beyond and above the influence of the magnetic field producedby the'magnetic device within the drum and guiding the path of said beltso that the material thereon separates from the belt when the beltleaves the magnetic field and while the belt is in engagement with saiddrum, means positioned adjacent the belt at a point the material on thebelt passes beyond the influence of the magnetic field, said meansreceiving the said material released from the belt and discharging thesame.

3. A magnetic separator comprising a first drum and 'a second drum eachmounted for rotation, the axes of said drums being essentiallyhorizontal and parallel with each other, the periphery of the said drumsat adjacent portions being spaced apart, an endless nonmagnetic beltengaging the said drums upon the peripheral portion thereof, andtraveling upon said peripheral portion, a magnetic device associatedwith each drum for producing a magnetic field at the lower portion ofeach drum where the belt is in peripheral contact with the drum, meansintermediate the drums and located above the horizontal diameter of eachdrum for looping the belt between the drums whereby portions of the saidbelt continue in engagement with the peripheral surfaces of the adjacentdrums to a point above and beyond the field produced by the magneticdevice of each drum, a hopper located beneath each of said drums, achute-for delivering material to be processed at the lower portion ofthe periphery of the first drum, a shed member located between the saiddrums and adapted to receive the magnetically separated: material fromthe first drum, a chute contiguous to said member for receiving materialtherefrom and directing it toward the lower peripheral portion of thesaid second drum and means located beneath the outer portion of thesecond drum for receiving material dropping from'the said belt and adelivery chute contiguous to said means for receiving the finallyseparated material.

4-. Atmagneticseparator comprisinga first drum and a second drumeachmounted for rotation, the axes of said drums being essentiallyhorizontal and parallel with each other, the periphery ofthe'said drumsat adjacent portions being spaced apart, an endless nonmagnetic beltengaging the said drums upon the peripheral portion thereof, andtraveling upon said peripheral: portion, a magnetic device associatedwith eachdrum for producing a magnetic field at the lower portion ofeach. drum where the belt is in peripheral contact with the drum, meansintermediate the drums and located above the horizontal diameter of eachdrum for'looping the belt between the drums whereby portions: of thesaid belt continue in engagement with the peripheral surfaces of theadjacent drums to a point above and beyond the field produced by themagnetic device of each drum, a hopper located beneath each of saiddrums, a chute for delivering material to be processed at: the lowerportion of the periphery of the first drum, a shed member locatedbetween the said drums and adapted to receive the magnetically separatedmaterial: from the first drum, achute contiguous to said member forreceiving material therefrom and directing it toward the lowerperipheralportion of the said second drum: and means located beneath theouter portion of the second drum for receiving material dropping fromthe said belt, adelivery chute contiguous to said means for receivingthe finally separated: material, water delivery means located betweenthe said drums and delivering water upon the belt at the inner side ofthe first drum, water delivery means located. adjacent the outer portionof the second drum for delivering water upon the said beltand assist inthe delivery of the processed material therefrom.

5. A magnetic separator comprising a first drum and a second drum theaxes of said drums being essentially horizontaland parallel witheachother, the periphery of thesaid drums at adjacent portions beingspaced apart, an endless non-magnetic belt engaging the said drums uponthe peripheral portions thereof and traveling upon saidperipheralportions, a magnetic device associated with each drum for producing amagnetic field at the lower portion of each drum where the belt is inperipheral contact with the drum, a rotatable cylindrical member mountedintermediate the drums and located above the horizontal diameter of eachdrum for looping the belt between the drums whereby portions of saidbelt continue in engagement with the peripheral surface of the adjacentdrums to a point above and beyond the field produced by the magneticdevice of each drum, a hopper located between each of said drums, achute member located adjacent the outer portion of the first-mentioneddrum for delivering material to be processed into contact with the belton the first drum adjacent the lower portion of the drum, a shed memberlocated between the adjacent portions of the drum adapted to deflectmaterial dropping from the belt at the inner portion of thefirst-mentioned drum, a chute contiguous to said shed member fordelivering material from the shed member to the belt at the lowerportion of the second drum adjacent thereto, a shed member locatedadjacent the outer portion of the second-mentioned drum to deflectmaterial dropping from the belt, and a delivery chute associated withsaid second-mentioned shed member.

6. A magnetic separator comprising a first drum and a second drum theaxes of said drums being essentially horizontal and parallel with eachother, the periphery of the said drums at adjacent portions being spacedapart, an

tinue in engagement with the peripheral surface of the adjacent drums toa point above and beyond the magnetic field producedby the magneticdevice of each drum, a hopper located between each of said drums, achute member located adjacent the outer portion of the firstmentioneddrum for delivering material to be processed into contact with the belton the first drum adjacent the lower portion of the drum, a shed memberlocated between the adjacent portions of the drum adapted to deflectmaterial dropping from the belt at the inner portion of thefirst-mentioned drum, a chute contiguous to said shed member fordelivering material from the shed member to the belt at the lowerportion of the second drum adjacent thereto, a shed member locatedadjacent the outer portion of the second-mentioned drum to deflectmaterial dropping from the belt, a delivery chute associated with saidsecond-mentioned shed member, water delivery means located between thesaid drums and delivering water upon the belt which is in contact withthe inner portion of the first-mentioned drum to assist in partingmaterial from the said belt, water delivery means located adjacent theouter portion of the second drum and delivering water upon the belt incontact with the periphery of the second-mentioned drum at a point abovethe shed which is associated with the outer portion of thesecond-mentioned drum.

7. A magnetic separator comprising a horizontal drum mounted forrotation upon its axis, a chute provided with a discharge end fordelivering material to a point adjacent the lower portion of the drum,an endless belt engaging the periphery of the said drum and includingthe lower portion thereof adapted to travel in the same direction as thedrum is rotated, the direction of rotation of the drum being such thatthe travel of the belt is in the same direction as material movingthrough the chute, the said chute directing the material into contactwith the belt, a hopper mounted beneath said drum, rotatable beltsupporting means mounted at the side of the drum in the direction ofbelt travel, stationary magnetic means within the said drum for creatinga magnetic field at the lower portion of the drum and below a horizontalplane through the axis of the drum, said rotatable supporting meansengaging with the belt and biasing the belt so that it engages with aconsiderable area of the lower drum surface to a point above theinfluence of the magnetic field on said side of the drum and guiding thebelt in a path such that the belt leaves the drum substantiallytangential to the drum at a horizontal diameter whereby the materialseparates from the belt when the belt leaves the influence of themagnetic field and while the belt is in engagement with the drum, andmeans located ad jacent the drum and the point thereof where the beltpasses out of the influence of the magnetic field for receiving themagnetic separated material from the belt and discharging said material.

8. A magnetic separator comprising a horizontal drum mounted forrotation about its axis, an endless belt engaging with a portion of theperiphery of said drum in-.

cluding the lower portion of the drum and adapted to travel in thedirection of rotation of the drum as the drum is rotated, a hoppermounted beneath the said drum, a chute for delivering material to thebelt upon the periphery of the drum and adjacent the lower portion ofthe said drum, a magnetic device within the drum for creating a magneticfield at the lower portion of the drum, means engaging with the belt andlocated at the side of the drum in the direction of belt travel forbiasing the belt so that it will travel in contact with the peripheralsurface of the drum on the said side thereof to a point beyond and abovethe magnetic field of the magnetic device within the drum, means fordelivering water upon the belt at a position immediately above themagnetic field and in proximity to the point where the belt leavescontact with the periphery of the drum, a shed located at one side ofand beneath that portion of the drum Where the belt leaves the drum andpasses to the means which biases the movement of the belt, said shedhaving a surface which cooperates with the hopper and having an oppositesurface which deflects magnetically separated material away from thesaid-mentioned drum.

Cane Feb. 9, 1892 Dutton July 13, 1915

